Posted on 5/29/2026
A misfire can feel obvious, or it can be sneaky. Sometimes the engine shakes at a stoplight like it wants your attention. Other times, the car only stumbles for one second when you climb a hill or press the gas to merge. That little stumble matters. A misfire means one cylinder is not burning fuel the way it should. Spark plugs and ignition coils are common causes, but a good mechanic does not start by throwing both at the car and hoping the light stays off. The job is to prove which cylinder is acting up and why. What A Misfire Feels Like Most drivers describe a misfire as shaking, hesitation, jerking, or a rough idle. It can happen when the engine is cold, once it warms up, under acceleration, or only at highway speed. The timing gives useful clues. A worn spark plug may show up more under load because the spark has a harder job when cylinder pressure rises. A weak ignition coil may act fine when cold, then fail once heat builds under the hood. If the check engi ... read more